This invention relates generally to the apparatus and method used to electrostatically develop and transfer the developed image to a receiving surface. More specifically, it pertains to the use of a method and apparatus that transports a master in a first direction, while applying a charge and developing the charged master with toner particles, and in the second direction transfers the developed image to the receiving surface from a stationary master. The master is cleaned while the master returns in the second direction. The method and apparatus are used in the transfer of a high resolution image to a receiving surface in either a single or multiple imaging mode.
The permanent master and the substrate supporting the permanent master are used as part of a system to repeatedly produce high resolution and high quality images on receiving surfaces. These receiving surfaces can be conductive, such as printed circuit boards, or nonconductive, such as paper or plastic which may be used in color graphic applications. Conductive receiving surfaces, such as printed circuit boards, have traditionally been produced by individually laminating, exposing, developing, etching and stripping processes where dry film photoresist has been used to produce the conductive wiring patterns. Previously, however, there has been no method or apparatus available to produce a plurality of copies of conductive wiring patterns from a single master copy of the desired wiring pattern utilizing photoimaging and a photopolymer in an apparatus that occupied a relatively small "footprint" in a manufacturing environment. There are many other factors which have prevented this type of system from being employed in manufacturing multiple copies from a single master.
Similarly, the use of an apparatus and method employing a photopolymer in conjunction with nonconductive receiving surfaces, such as those used in color graphics, has not previously been possible in a small "footprint" apparatus that provided high speed and high quality copies. Offset lithography has utilized an apparatus and method that employs two directionally operating image transfer systems with a transfer roller.
The ability to precisely position the master on the supporting substrate and to accurately and repeatedly position it on or over the receiving surface to obtain the necessary tolerances and repeated copies has been a continuing problem.
These problems are solved in the design of the present invention which utilizes a two directionally operating apparatus and method to charge and develop the master in a first direction and transfer the developed master in a second direction.